Post on 20-Mar-2018
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Avocado research at the E.E. la Mayora,
Malaga, Spain- Latitude: 36º 45’ N- Temperatures (last 40 years)
- Average: 19.4ºC:- 29.4ºC (average highs in August)- 9.3 ºC (average lows in January)- Lowest temp on record: 0.5ºC in
January 2005- Rainfall: 435 mm year
La Mayora Experimental Station
• Commercial avocado orchards started to be planted in the 1970s.
• Original plantings: seeds imported from Mexico as rootstocks (Topa Topa) and grafted with commercial varieties such as Hass and Fuerte.
• Spain produces about 1/3 of European consumption
• Current situation: • Rootstocks obtained from seeds and Duke 7
• Main cultivar Hass (more than 70% of surface) followed by Fuerte and Bacon
• Main problems: – soil fungi: Phytophthora and
Rosellinia– Persea mite: Olygonichus perseae
AVOCADO IN SPAIN Main avocado research lines at the E.E. la Mayora
Spanish Council for Scientific Research
LA MAYORA EXPERIMENTAL STATION
Optimization of avocado cultural techniques
Organic production:Study of the effects of low or no mineral N supply on yield, tree growth and fruit quality using different mulching applications
MicroelementsDifferent doses and soilaplication methods for B, Zn andCu have been evaluated for thelast 12 years.
Pruning:Different pruning dates in summerare being studied.
Alternate irrigation:Alternate irrigation is beingcompared with conventionalirrigation on yield, tree growth androot system development as a promising tool to control soil-borne diseases.
Postharvest management:Study of the effects of some T-RH combinations and different physicaland chemical treatments on fruitrots
Plant Material
Molecular fingerprintingFingerprinting of the germplasm collection: about 30 local and 60 foreign genotypes
Agronomic evaluation of different cultivarsA dynamic cultivar collection, including several Hass-likeselections from all over the world is being evaluated for traits of agronomic interest
Coefficient0.23 0.42 0.62 0.81 1.00
LACONSULA12MW
SAN JAVIER 13 LA CONSULA 12 SAN JAVIER 8 SAN JAVIER 19 SAN JAVIER 12 SAN JAVIER 1 SAN JAVIER 6 SAN JAVIER 11 SAN JAVIER 4 SAN JAVIER 29 SAN JAVIER 28 LA CONSULA 6 LA CONSULA 9 MEXICOLA SCOTT THOMAS BUENO LA PISCINA ALHAURIN BENTAVOL GAR DUKE PARENT DUKE 6 DUKE 7 FITO CHINEA BENTAVOL INV CUPANDA G6 SCHIDMT MARVEL (BL 516) BACON LULA SAN JAVIER 14 COÍN TOPA TOPAHARVEST LONHEIS SHIAPACASSE JIMENEZ 2 HASS MOTRIL EUGENIUM H670 HASS TACAMBARO JIMENEZ 1 SIR PRIZE OA184 FUNDACIÓN 2 REGAL ADI NOBEL (BL667) BL122 GEM BL5556 IRIET MONSALVE EL VISO VILLENA FUERTE ACUEDUCTOS RR86 COLIN V33 SHEPARD RINCOATL EDEN PINKERTON TORO CANYON NEGRA DE LA CRUZLONJAS SRA. CHINEA CLAVERO 2 MAOZ ANAHEIM GVAR13 FUSCH 20 G755A
Similarity0.23 0.42 0.62 0.81 1.00
LACONSULA12MW
SAN JAVIER 13 LA CONSULA 12 SAN JAVIER 8 SAN JAVIER 19 SAN JAVIER 12 SAN JAVIER 1 SAN JAVIER 6 SAN JAVIER 11 SAN JAVIER 4 SAN JAVIER 29 SAN JAVIER 28 LA CONSULA 6 LA CONSULA 9 MEXICOLA SCOTT THOMAS BUENO LA PISCINA ALHAURIN BENTAVOL GAR DUKE PARENT DUKE 6 DUKE 7 FITO CHINEA BENTAVOL INV CUPANDA G6 SCHMIDT MARVEL (BL 516) BACON LULA SAN JAVIER 14 COÍN TOPA TOPAHARVEST LOHNEI SSSHIAPACASSE JIMENEZ 2 HASS MOTRIL EUGENIM H670 HASS TACAMBARO JIMENEZ 1 SIR PRIZE OA184 FUNDACIÓN 2 REGAL ADI NOBEL (BL667) LAMB HASS (BL122) GEM BL5552 IRIET MONSALVE EL VISO VILLENA FUERTE ACUEDUCTOS RR86 COLIN V33 SHEPARD RINCOATL EDEN PINKERTON TORO CANYON NEGRA DE LA CRUZLONJAS S. CHINEA CLAVERO 2 MAOZ ANAHEIM GVAR13 FUCHS 20 G755A
6456
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6264 5250
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Reproductive biology and optimization of yieldA correct understanding of the floral biology of avocado under our environmental conditions is necessary to optimize yield
Pollination: Effects of different pollinizers on alogamy rate and yield
Flower Quality: Study of the causes behind flower abscission: starch content of individual flowers at anthesis and itsrelation with flower fate
Study of the progamic phase and the effects of environment (temperature and humidity) on the dichogamous cycle
Incidence and development of strategies for the biological control of Persea mite
• Important pest in avocado in Spain since 2004
• Current studies directed towards evaluating the incidence of the pest and to develop adequate strategies ofbiological control.
• The presence of different types of pollen on avocado plants seems to increase phytoseiid populations in spring: pollen applications could be a promising tool to control mite populations in the field.
Optimization of genetic transformation
Fernando Pliego, University of Malaga
CHEMICAL CONTROL
GENETIC CONTROLUse of resistant / tolerant rootstocks
BIOLOGICAL CONTROLUse of antagonistic microorganisms which
reduce the disease (Sordaria, Thichoderma, bacterial strains)
REGULATION AND CULTURAL METHODS
Remove the infected plants, irrigation control, use of organic amendements
INTEGRATEDMANAGEMENT
SOLARIZATION
PHYSICAL CONTROL
Control of avocado white rot. Rosellinia necatrix
University of MalagaIFAPA
Phase 0: pruning of escape trees int he field
Phase I: establishmentin vitro
Phase II:proliferation
Phase III: rooting Phase IV: acclimatation
Multiplication in vitro of escape trees or seedlings
Selection of avocado rootstocks tolerant to Rosellinia necatrix
Avocado trees surviving in orchards infected with R. necatrix
Seedlings from different origins(Mexico, Australia, Spain)
Araceli BarceloIFAPA
Seedlings after inoculation
Artificially infested plot
RESEARCH ON AVOCADO REPRODUCTIVE BIOLOGY AT THE E.E. LA MAYORA, MÁLAGA SPAIN
♀ ♂
Overlap
Protogynousdichogamy
2 TYPES OF CULTIVARSA and B
AVOCADO CHARACTERIZED BY LOW FRUIT SET
Massive drop of flowers and developing fruitlets
Some unpollinated flowers Inadequate pollination
Other factors must be involved
OBJECTIVES
1.1. ENVIRONMENTAL FACTORS AFFECTING THE PROGAMIC PHASEENVIRONMENTAL FACTORS AFFECTING THE PROGAMIC PHASE
2. NUTRITIVE STATUS OF THE FLOWERS AT ANTHESIS2. NUTRITIVE STATUS OF THE FLOWERS AT ANTHESIS
3. EFFECT OF CROSS3. EFFECT OF CROSS--POLLINATION ON YIELD AND OUTCROSSINGPOLLINATION ON YIELD AND OUTCROSSING
4. OPTIMIZING THE CHOICE OF POLLINIZERS4. OPTIMIZING THE CHOICE OF POLLINIZERS
OBJECTIVES
1.1. ENVIRONMENTAL FACTORS AFFECTING THE PROGAMIC PHASEENVIRONMENTAL FACTORS AFFECTING THE PROGAMIC PHASE
2. NUTRITIVE STATUS OF THE FLOWERS AT ANTHESIS2. NUTRITIVE STATUS OF THE FLOWERS AT ANTHESIS
3. EFFECT OF CROSS3. EFFECT OF CROSS--POLLINATION ON YIELD AND OUTCROSSINGPOLLINATION ON YIELD AND OUTCROSSING
4. OPTIMIZING THE CHOICE OF POLLINIZERS4. OPTIMIZING THE CHOICE OF POLLINIZERS
Pollen adhesion and germination observed both in female and male stages
EFFECT OF TEMPERATURE ON POLLEN ADHESION AND
GERMINATION
No
adhe
red
polle
n gr
ains
Temperature
Field
Field
Temperature
% P
olle
n ge
rmin
atio
n
Female Male
Female Male
EFFECT OF RELATIVE HUMIDITY ON POLLEN
ADHESION AND GERMINATION
No
adhe
red
polle
n gr
ains
Female
Female
Male
Male
% P
olle
n ge
rmin
atio
n
Relative humidity
Relative humidity
Stigma
Style 1/4
Style 1/2
Style 3/4
Ovary
Ovule
Time after pollination (hours)
EFFECT OF TEMPERATURE ON POLLEN TUBE GROWTH
20oC
30oC
10oC
2 4 86 24 30 48hours
No temp effect on
ovule viability
% fruit set similar between on and off years
% fl
ower
s/fr
uits
set
% fl
ower
s/fr
uits
set
Weeks after end of flowering
Weeks after end of flowering
OBJECTIVES
1.1. ENVIRONMENTAL FACTORS AFFECTING THE PROGAMIC PHASEENVIRONMENTAL FACTORS AFFECTING THE PROGAMIC PHASE
2. NUTRITIVE STATUS OF THE FLOWERS AT ANTHESIS2. NUTRITIVE STATUS OF THE FLOWERS AT ANTHESIS
3. EFFECT OF CROSS3. EFFECT OF CROSS--POLLINATION ON YIELD AND OUTCROSSINGPOLLINATION ON YIELD AND OUTCROSSING
. OPTIMIZING THE CHOICE OF POLLINIZERS. OPTIMIZING THE CHOICE OF POLLINIZERS
I2KI
No.
of f
low
ers
Optical density x104
- NO EXTERNAL DIFFERENCES AMONG FLOWERS- GREAT DIFFERENCES IN STARCH CONTENT
1st Row
2nd Row
3rd Row
4th Row Opt
ical
den
sity
x10
4
Place in the inflorescence
1st row 2nd row 3rd row 4th row
Opt
ical
den
sity
x10
4
Early flowers Late flowers
Differences in starch content between two populations of flowers with different capacity to set fruits STARCH CONTENT IN INDIVIDUAL FLOWERS AND FRUIT SET
Opt
ical
den
sity
x10
4
Dropped Retained
OBJECTIVES
1.1. ENVIRONMENTAL FACTORS AFFECTING THE PROGAMIC PHASEENVIRONMENTAL FACTORS AFFECTING THE PROGAMIC PHASE
2. NUTRITIVE STATUS OF THE FLOWERS AT ANTHESIS2. NUTRITIVE STATUS OF THE FLOWERS AT ANTHESIS
3. EFFECT OF CROSS3. EFFECT OF CROSS--POLLINATION ON YIELD AND OUTCROSSINGPOLLINATION ON YIELD AND OUTCROSSING
4. OPTIMIZING THE CHOICE OF POLLINIZERS4. OPTIMIZING THE CHOICE OF POLLINIZERS
Background
Increase distance to the pollen donor source
Outcrossing rate Yield
(Vrecenas-Gadus and Ellstrans, 1985Goldring et al., 1987)
(Bergh and Gustafson, 1958Bergh and Garber, 1964Bergh et al., 1966Bergh, 1968)
Contradictory results Goldring et al., 1987Johannsmeier et al., 1989Garner et al., 2008
Selective fruit drop Most fruits in the tree result of cross-pollination
OUTCROSSING RATE IN AN SOLID HASS BLOCK OPPOSITE TO A SOLID FUERTE BLOCK
1034
956958
995997999
1038 1036
Hass
960
875879 877
Fuerte
20-30 fruits per tree: DNA extraction from the embryos
AVAG21
Hass186/201
Fuerte 183/203
Fuerte
Hass
SSR analysis
Pearson correlation coefficient
Cross‐fertilization Distance to the pollen source
‐0.7 (p= 0,014)
Row 1 Row 2 Row 3
Out
cros
sing
rate
p= 0,01
Row 1 Row 2 Row 3
Out
cros
sing
rate
No significant effect of the distance to the pollen source was found during 13 years
FRUIT DROP
July August
Mid fertil.
Early fertil.
85% 48%
% of cross-fertilization
% of dropped flowers related to date of fertilization
Hass Fuerte Hass Fuerte
Out
cros
sing
rate
Months after anthesis
OBJECTIVES
1.1. ENVIRONMENTAL FACTORS AFFECTING THE PROGAMIC PHASEENVIRONMENTAL FACTORS AFFECTING THE PROGAMIC PHASE
2. NUTRITIVE STATUS OF THE FLOWERS AT ANTHESIS2. NUTRITIVE STATUS OF THE FLOWERS AT ANTHESIS
3. EFFECT OF CROSS3. EFFECT OF CROSS--POLLINATION ON YIELD AND OUTCROSSINGPOLLINATION ON YIELD AND OUTCROSSING
4. OPTIMIZING THE CHOICE OF POLLINIZERS4. OPTIMIZING THE CHOICE OF POLLINIZERS
SEARCHING FOR A POLLINIZER FOR HASS
Requeriments
Type B
Overlap in flowering time with Hass
Currently in Spain Fuerte is used
Not enough overlap
If possible: Hass-like fruits
Study of the flowering season of 27 cultivars
VARIEDADES ADI HASS MOTRIL BL 5552 IRIET BL122 JIMENEZ I BL516 JIMENEZ II BL667 LONHEISS COLIN V-33 LONJAS EDEN NEGRA DE LA CRUZ FUERTE OA 184 FUNDACIÓN II PINKERTON H670 REGAL GEM (3-29-5) RINCOATL HARVEST RT 5176 HASS SHEPARD CUPANDA
FLOWERING TIME
MARZO ABRIL MAYO13 16 19 22 25 28 31 3 6 9 12 15 18 21 24 27 30 3 6 9 12 15 18 21
FUERTECUPANDASHEPARDBL 122BL 5552BL 516NEGRA DE LA CRUZRT 5176JIMÉNEZ 1REGALH 670HASS MOTRILLONHEISEDENJIMÉNEZ 2BL 667LONJAS3-29-5IRIETHASSRINCOATLPINKERTONHARVESTCOLIN V-33FUNDACIÓN IIOA 184ADI
MARCH APRIL MAY
OVERLAP BETWEEN SEXUAL STAGES
Two trees per cultivar studied
11 cultivars selected
CULTIVARES HASS FUERTE BL 667 (NOBEL) BL 516 (MARVEL) BL 122 3-29-5 (GEM) JIMÉNEZ 2 JIMÉNEZ 1 HASS T. MOTRIL TACAMBARO H 670
Flower stage followed every 2 hours: 8:00‐ 20:00
Sexual stage Overlap% Male flowers
% Female flowers
OVERLAP IN SEXUAL STAGES BETWEEN FLOWERS OF 11 CULTIVARS
HASS
FUERTE
NOBEL
MARVEL
LAMB HASS
GEM
JIMENEZ 2
JIMENEZ 1
LOHNEISS
HASS MOTRIL
TACAMBARO
H670
8:00 10:00 12:00 14:00 16:00 18:00 20:00
*
*
*
*
*
*
*
Estado femenino Estado masculinoFemale stage Male stage
OVERLAP AT THE BEGGINING OF FLOWERING SEASON
HASS
FUERTE
NOBEL
MARVEL
LAMB HASS
GEM
JIMENEZ 2
JIMENEZ 1
LOHNEISS
HASS MOTRIL
TACAMBARO
H670
8:00 10:00 12:00 14:00 16:00 18:00 20:00
*
*
*
*
*
*
*
Estado femenino Estado masculino
*
*
*Female stage Male stage
OVERLAP AT THE END OF THE FLOWERING SEASON
HASS
FUERTE
NOBEL
MARVEL
LAMB HASS
GEM
JIMENEZ 2
JIMENEZ 1
LOHNEISS
HASS MOTRIL
TACAMBARO
H670
8:00 10:00 12:00 14:00 16:00 18:00 20:00
*
*
*
*
*
*
Estado femenino Estado masculino
*
Male stageFemale stage
% Fruit set after hand-pollinations
BL 667 (NOBEL) 8,4%
BL 516 (MARVEL) 7,4%
FUERTE 2,8%
CONCLUSIONS
Avocado shows a fast progamic phase. This phase is clearly affect by environmental conditions: high temperatures increase pollen tube
growth and low temperatures increase the time required for fertilization
Under conditions of 20-25ºC and high relative humidity, the estigma conserves the capacity to allow germination and pollen tube growth in
the male stage, favoring self-pollination Differences in yield between on and off years are due to the intensity offlowering since fruit set % is not significantly different
The nutritive status of the pistil is related to the reproductive success ofthe flower, since differences are observed in starch content among
flowers at anthesis. Starch content is higher in flowers that will set fruit. Thus, the nutritive status of the flower seems to be a necessary condition,
but not the only one, for fruit set
The distance between two complementary cultivars (‘Hass’ and‘Fuerte’) has an effect on cross fertilization; however, there are no
differences in yield with increasing distance
The genotype of the embryo does not seem to be determinant in selectivefruit drop during the months following anthesis; the fruits that drop are
preferently those fertilized at the end of the ‘Hass’ flowering season. Those fruits are mainly the result of self-fertilization since no flowers of
‘Fuerte’ are present at the end of the ‘Hass’ flowering season
Taking into account the length of the flowering season, the overlapbetween sexual stages and yield, ‘Marvel’ (BL516) and ‘Nobel’ (BL667) could be interesting pollinizers for ‘Hass’ under our growing conditions